Calcitonin Gene-Related Peptide Receptor Activation by Receptor Activity-Modifying Protein-1 Gene Transfer to Vascular Smooth Muscle Cells

Zhongming Zhang, Ian M. Dickerson, Andrew F. Russo
2006 Endocrinology  
The neuropeptide calcitonin gene-related peptide (CGRP) is a potent vasodilator that plays a protective role in the cardiovascular system. The receptor for CGRP is an unusual complex of the G protein coupled calcitonin-like receptor (CLR) and an obligate receptor activity modifying protein-1 (RAMP1). In this report we provide the first evidence that RAMP1 is rate-limiting in vascular smooth muscle cells. While cultured rat aorta smooth muscle cells express CLR and RAMP1, we found that CGRP is
more » ... ound that CGRP is not a potent activator of the receptor. Following overexpression of RAMP1 by adenoviral gene transfer there was a striking increase in CGRP induced production of cAMP, with a 75-fold decrease in the EC 50 and a 1.5-fold increase in the maximal response. The biological consequence of this increased receptor activity was observed in three different paradigms. First, RAMP1 gene transfer caused a CGRP-dependent decrease in cell proliferation. Second, RAMP1 and CGRP treatment led to a 3-fold greater free-radical induced reduction in cell number. Finally, RAMP1 gene transfer resulted in a 5-fold CGRP-dependent increase in TUNEL-positive apoptotic cells upon serum withdrawal. The mechanisms underlying these effects involved cAMP-dependent pathways. We propose that RAMP1 gene transfer may be an effective strategy for increasing the effectiveness of CGRP-induced decrease in restenosis following aortic angioplasty. 13), although its requirement as a chaperone is controversial (14, 15). Two additional RAMPs (RAMP2 and RAMP3) share ~30% identity with RAMP1. Co-expression of RAMP2 or 3 with CLR yields adrenomedullin receptors (11, 16, 17). Adrenomedullin and CGRP have overlapping activities, including blood vessel dilation (4). The CGRP receptor in vascular smooth muscle is coupled to cAMP production (18, 19), and this coupling is facilitated by RCP, an intracellular protein that co-immunoprecipitates with the CLR/RAMP complex (20). Zhang et al. 4 SR 1985 Distribution and origin of calcitonin gene-related peptide (CGRP) immunoreactivity in the sensory innervation of the mammalian eye. Journal of Comparative Neurology 233:506-16 2. Uddman R, Edvinsson L, Ekblad E, Hakanson R, Sundler F 1986 Calcitonin generelated peptide (CGRP): perivascular distribution and vasodilatory effects. Regul Pept 15:1-23 3. Brain SD, Williams TJ, Tippins JR, Morris HR, MacIntyre I 1985 Calcitonin generelated peptide is a potent vasodilator. Nature 313:54-6 Zhang et al. 18 4. Brain SD, Grant AD 2004 Vascular actions of calcitonin gene-related peptide and adrenomedullin. Physiol Rev 84:903-34 5. Lechleitner P, Genser N, Mair J, Dienstl A, Haring C, Wiedermann CJ, Puschendorf B, Saria A, Dienstl F 1992 Calcitonin gene-related peptide in patients with and without early reperfusion after acute myocardial infarction. Am Heart J 124:1433-9 6. Wang W, Sun W, Wang X 2004 Intramuscular gene transfer of CGRP inhibits neointimal hyperplasia after balloon injury in the rat abdominal aorta. Am J Physiol Heart Circ Physiol 287:H1582-9 7. Muff R, Born W, Lutz TA, Fischer JA 2004 Biological importance of the peptides of the calcitonin family as revealed by disruption and transfer of corresponding genes. Peptides 25:2027-38 8. Durham PL 2004 CGRP receptor antagonists: a new choice for acute treatment of migraine? Curr Opin Investig Drugs 5:731-5 9. Juaneda C, Dumont Y, Quirion R 2000 The molecular pharmacology of CGRP and related peptide receptor subtypes. Trends in Pharmacological Sciences 21:432-8
doi:10.1210/en.2005-0918 pmid:16373421 fatcat:zezw4jby65eq7gtvkjtc45wqwq